Pascal’s triangle, as the name implies, is a collection of numbers in the shape of a triangle. Each number in the triangle is the sum of the two directly above. For example, in the accompanying illustration, the 6 on line 5 is the sum of the pair of 3’s above; the next line is 1, 10 (1 + 9), 45 (9 + 36), 120 (36 + 84), and so on. Although the triangle was known to both the Chinese and the Arab cultures for several hundred years before, it was named after the person who brought it to the forefront of mathematics: French mathematician Blaise Pascal (1623–1662). (For more information about Pascal, see “History of Mathematics.”)